DNS-based email trust signals
Email Authentication Checker
Check public SPF, DMARC, optional DKIM, and MX signals for a domain and learn what they mean.
Tool guidance
How to use this tool
Only the domain and optional selector are sent to CheckLink for DNS lookup.
How to use it
Enter a domain, not a full URL.
Optionally enter a DKIM selector if you know it.
Run the DNS check and review SPF, DMARC, optional DKIM, and MX records.
Use the result to understand configuration signals.
What results mean
SPF, DKIM, and DMARC presence is useful, not a guarantee.
Missing or weak records can increase spoofing risk.
DNS checks are server-side because public DNS must be queried.
What to do next
Inspect a real message with Email Header Inspector.
Read the SPF/DKIM/DMARC guide.
Request brand monitoring or business review if customers receive spoofed messages.
Browser extension
CheckLink browser extension
Open the current page, inspect links from the browser menu, and jump into CheckLink faster without an account.
Works with Chrome and compatible Chromium-based desktop browsers. Firefox and Safari versions are not currently available.
The extension sends a URL only when you choose a scan action. It does not store scan history.
DKIM records require a selector. If you do not know it, SPF, DMARC, and MX can still be checked.
Domain signals
Enter a domain to check public email authentication records.